JPH04279808A - Paste solder printing condition inspection device - Google Patents

Abstract

PURPOSE:To inspect accurately and rapidly a paste solder printing condition by conducting the automatic generation of an inspection data file by means of a conversion means, conducting the automatic setting of a quality decision reference by means of a setting means, and conducting the comparative decision of the inspection data file and data from a photographed image by means of the quality decision reference. CONSTITUTION:Screen printer data is received from a host computer 12, and converted automatically into inspection data, and a quality decision reference is set. An inspection object print base 10 is moved to an initial position by means of an XY table 1, and an image is housed into an input image memory 8a by means of a CCD camera 3. In this instance, an illumination controller 6 is irradiating predetermined illumination. While the image at the memory 8a is being processed by a computer device 5, the table 1 is moved to the next visual field, and the next visual field image is housed at 8b. Meanwhile, the computer device 5 processes it the instant image processing at the memory 8a is completed. Inspection is conducted in parallel with movement to the next visual field image input image processing.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paste solder printing condition inspection apparatus that automatically and rapidly inspects the printing condition of paste solder printed on a printed circuit board using a phase shift method.

0002

2. Description of the Related Art In recent years, as electronic devices have become smaller and more sophisticated, electronic components have become smaller, and high-density mounting of printed circuit boards has become an important issue. Due to miniaturization of lands on printed circuit boards and narrowing of their spacing, mounting of electronic components on printed circuit boards has largely relied on surface mounting technology using a reflow method using paste solder. Under these circumstances, although the inspection of component mounting and soldering conditions is becoming increasingly automated, the printing condition when paste solder is printed on printed circuit boards is either not inspected at all or is not inspected at all. However, the reality is that we rely on visual inspection methods, which are extremely unreliable.

0003

[Problem to be Solved by the Invention] However, defects in the soldering condition of components are largely caused by the printing condition of the paste solder on the printed circuit board, so it is necessary to inspect the printing condition immediately after printing the paste solder to prevent defects. need to be eliminated. Furthermore, it is necessary to have a processing speed equal to or higher than that of production equipment in inspection within the production line, and to detect defects in the production line in real time. Up until now, we have relied on manual labor, and visually inspecting a large number of minute objects in a short period of time is a demanding task, and it is also prone to inspection omissions and inspection errors, leading to inefficiencies. It was the cause.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an apparatus for accurately and quickly inspecting the printing condition of paste solder immediately after printing.

[0005]

[Means for Solving the Problems] The paste solder printing state inspection apparatus of the present invention includes a means for setting a printed circuit board of printed paste solder before component mounting on a reciprocating stage, and a means for setting the printed circuit board on a reciprocating stage, and projection means for projecting a grid pattern using a liquid crystal light valve onto a grid; imaging means for capturing an image of the grid pattern projected onto the printed circuit board by the projection means; A recognition means for recognizing the volume and position of the paste solder by driving the liquid crystal light valve using the principle of a phase shift method (fringe scanning method) and a determination of the quality of the paste solder printing state are incorporated in advance. The present invention is characterized by comprising a determination means that performs determination by comparing ideal shape image information and the captured image.

Furthermore, the ideal shape image information is the CA of the screen mask of the screen printing machine that prints the solder paste.
A host computer input as D data, and a conversion means for automatically generating an inspection data file by downloading the CAD data from the host computer, and the judgment means makes a judgment using the inspection data file. Features.

[0007]Furthermore, the present invention is characterized in that it includes a setting means for automatically setting a pass/fail judgment criterion by teaching using a non-defective sample, and the judging means makes a judgment using the pass/fail judgment criterion.

[0008]

[Operation] In the apparatus of the present invention, an inspection data file is automatically generated by a conversion means such as a data conversion machine, and a pass/fail judgment criterion is automatically set by a setting means. are compared and judged based on the above-mentioned pass/fail criteria, and tested accurately and quickly.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the paste solder printing condition inspection apparatus of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a diagram showing the configuration of an inspection apparatus according to this embodiment. It is equipped with an XY table 2 on which a printed circuit board 10 is placed, and a CCD camera 3 that takes an image of this printed circuit board 10 from above. On the printed circuit board 10, solder paste 10a is printed in a convex shape. CCD camera 3
is the printed circuit board 10 set by the XY table 1
The upper predetermined inspection area is imaged and an image signal is output. This inspection area is illuminated by a lighting device 2. (For example, in the case of the phase shift method, lattice stripes are projected.) The imaged inspection area is subjected to predetermined processing by the computer device 5, and the volume, area, etc. of the solder paste are calculated. At that time, the image memory is 8a, 8
There are 2 sets of b. The controller 9 comprehensively controls the computer device 5, the XY controller 4, the lighting controller 6, and the image memories 8a and 8b.

The inspection procedure will be explained with reference to the flowchart shown in FIG. First, the CAD data of the screen mask of the screen printing machine is received from the host computer 12.
Automatically converts AD data into various data used for inspection, and also sets pass/fail judgment criteria. Next, the printed circuit board 10 to be inspected is moved to the initial position by the XY table 1. Next, an image at the initial position is input using the CCD camera 3. The input image is stored in the image memory 8a. At this time, the lighting controller 6 is emitting predetermined lighting. While the computer device 5 is processing the image stored in the image memory 8a, the XY table 1 moves to the next field of view and stores the image of the next field of view in 8b. On the other hand, when the image processing in the image memory 8a is completed, the computer device 5 can process the next image immediately because the next image has already been input into the image memory 8b. In addition, the examination repeats the process of ``moving to the next visual field'' → ``image input'' → ``image processing'' in parallel.

0012

[Effects] By using the inspection device of the present invention, a processing speed equal to or higher than that of production equipment can be obtained in inspection within the production line, and defects can be detected in real time on the production line, improving production efficiency. Leads to improvement. Further, according to the paste solder printing condition inspection apparatus of the present invention, it is possible to perform a complete inspection within a production line.

Furthermore, since the functions of the system can be divided into a computer device for image processing and a controller that performs other controls, it is possible to promote device development for each function.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an inspection device according to an embodiment of the present invention.

FIG. 2 is a flowchart diagram of an embodiment.

[Explanation of symbols]

1: XY table, 2: lighting device, 3: CCD camera,
4: XY table controller, 5: computer device, 6: lighting controller, 7: distributor, 8a, 8b: image memory, 9: controller, 10: printed circuit board, 1
1: Data conversion machine, 12: Host computer

Claims (3)

[Claims] 1. Means for setting a printed circuit board with printed solder paste before component mounting on a reciprocating stage, and projection means for projecting a grid pattern using a liquid crystal light valve onto a solid grid from an oblique direction onto the printed circuit board. and,
an imaging means for taking an image of the lattice pattern projected onto the printed circuit board by the projection means; a recognition means for recognizing by using the principle of a shift method (fringe scanning method); and a determination means for determining whether the paste solder printing condition is good or bad by comparing the captured image with ideal shape image information captured in advance. A paste solder printing condition inspection device comprising: 2. A host computer into which ideal shape image information is input as CAD data for a screen mask of a screen printing machine that prints paste solder, and the CAD data is downloaded from the host computer to automatically generate an inspection data file. 2. The paste solder printing state inspection apparatus according to claim 1, further comprising a converting means, and wherein said determining means makes a determination using said inspection data file. 3. The paste solder according to claim 1, further comprising a setting means for automatically setting a pass/fail judgment criterion by teaching using a non-defective sample, and wherein the judging means makes a judgment using the pass/fail judgment criterion. Printing condition inspection device.